The first is selling items in the pseudo-auction house-retainer system. There is far more hassle then there needs to be when finding a price to sell an item. I think an easy fix for this if the retainer system will be continued would be to display a bubble with the current market prices when highlighting or selecting an item for transaction. This still wouldn't defeat having to enter the wards and locating your retainer to set this up but it would be far better than running to the end of the ward and looking up a price each time you want to sell an item.

The second is early content for new players. I'm not sure of everything planned for 2.0 for the wave of new players that is expected but as it stands currently for someone who starts not knowing any players there isn't much to do to gain levels that keeps most people interested in the game. Doing quests gives negligible experience and spamming leves is okay but tedious and hardly interesting at it's current state. There needs to be more for at early stages of the game to keep players interested.

The third is the way you are able to power level players. This completely kills any chance of being able to do lower level events with groups of players because those that have the higher level friends know they can get their levels anytime they want to. This also steals the sense of accomplishment from the players who earned their levels without power leveling. The current way you are able to power level players in the game is completely broken and needs to be revised. A simple fix is just having the mob give the exp of the highest person to deal damage. How it is now will cause some players to be turned off by the game for this simple reason.